The Characteristics of the pin-Structure with a Discrete Metallic Surface i-Region

Abstract

Introduction. Currently, an interest in improving pin-structures continues to be the focus of attention of developers of electronic devices. Devices that use controlled pin-structures include: non-volatile memory, static voltage protection device, pin-diodes with adjustable characteristics, etc. However, insufficient attention is paid to the issue of controlling the characteristics of pin-structures by using discrete metallization on the surface of i-region.Aim. Investigation of the influence of discrete metallization of the surface of i-region on static and dynamic characteristics of pin-structure, defect compensation, and efficiency control of the pin-photodetector.Materials and methods. The pin-structure under study consisted of p + -boron-doped region; n + -phosphorusdoped region; i-phosphorus-doped region; semi-insulating substrate; metallization of the substrate; polysilicon control gate; and a silicon oxide dielectric layer. Two-dimensional numerical analysis of the potential distribution, of the concentration of free charge carriers and currents was performed in the Synopsys Sentaurus TCAD environment.Results. Two-dimensional analysis of discretely metallized pin-structures was performed. The stresses applied to the gates of i-region that compensated the influence of defects formed by electron irradiation were determined. Four pin-photodetector structures were modeled, in which the control gates were performed in the form of metal–dielectric–semiconductor structure. The possibility of increasing the sensitivity of the pinphotodetector by applying the corresponding potentials to the gates was demonstrated.Conclusion. An effect of discrete metallization of i-region of the pin-structure was investigated. A method for correcting of the characteristics of the irradiated pin-diode to the initial characteristics was proposed. It makes possible to use such diodes in electronics with high requirements for operating in areas with high radiation. The design of a high-sensitivity photodetector with control gates on the surface of i-region and with the structure of low alloy i-region split into two regions (p- and n–type conductivity) was proposed.